<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <!-- 2. 使用set实现数组去重 -->
    <script>
        const arr = [1,2,2,3,3,4,4,5,6];
        const b = [...new Set(arr)];
        console.log(b);
    </script>
</body>
</html>